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<div class="moz-cite-prefix">On 2013-12-02 4:49 PM, Kevin Korb
<a class="moz-txt-link-rfc2396E" href="mailto:kmk@sanitarium.net"><kmk@sanitarium.net></a> wrote:<br>
</div>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<pre wrap="">A little Gentoo specific info here...
On 12/02/13 16:24, Leen Besselink wrote:
</pre>
<blockquote type="cite">
<pre wrap="">On Mon, Dec 02, 2013 at 02:31:23PM -0500, Charles Marcus wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hello,
I'm going to be moving a filesystem around, and was planning on
using rsync to do it, so like to get some advice from those more
experienced than I (both using rsync, and moving filesystems)...
I currently have a system that has a separate /usr on an LVM
partition.
I want to merge this back into the / (root) filesystem.
This is a production server (mail server, gentoo linux), so I'd
really like to not brick this thing in the process.
What would the best arguments to use for making sure that
everything is preserved properly for a smooth transition?
</pre>
</blockquote>
<pre wrap="">
I have some simple tips:
</pre>
<blockquote type="cite">
<pre wrap="">Some suggestions on the gentoo list have been:
-a, or -axAHX, or -apogXx, or -PvasHAX
or should I go with a combined -apogsvxAHPX ?
</pre>
</blockquote>
<pre wrap="">
I suggest you have a look at the output of rsync --help, it says:
-a, --archive archive mode; equals -rlptgoD (no
-H,-A,-X)
Clearly some of the ones you mention are already on that list.
There is no need to add them again.
</pre>
</blockquote>
<pre wrap="">
Agreed completely.</pre>
</blockquote>
<br>
Ok, so based solely on what is included in -a, the above could be
potentially shortened to:<br>
<br>
-apogsvxAHPX<br>
<br>
Then, after reading the following, looks like it could ultimately be
whittled down to:<br>
<br>
-avxHX --numeric-ids<br>
<br>
?<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">So what is stored in /usr ? Is there also a /usr/src ? or
/usr/local that has any content ?</pre>
</blockquote>
</blockquote>
<br>
Yes...<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<pre wrap="">OP was talking about booting from a live media so no sub-mounts would
be mounted so this shouldn't matter.</pre>
</blockquote>
<br>
There are no submounts.<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">-A can be useful if you have ACLs, lots of systems don't.
</pre>
</blockquote>
<pre wrap="">
ACLs are only supported if the filesystem is mounted with the acl
option so that is a simple way to check if it should be used (also you
will get errors if you try to write ACLs to a filesystem that isn't
mounted with that option).</pre>
</blockquote>
<br>
Apparently no acls.<br>
<br>
/dev/sda1 /boot ext2
noauto,noatime 1 2<br>
/dev/sda2 none swap
sw 0 0<br>
/dev/sda3 / ext3
noatime 0 1<br>
/dev/sda4 /backups ext3
noatime 0 2<br>
/dev/vg2/home /home reiserfs
noatime 0 0<br>
/dev/vg2/usr /usr reiserfs
noatime 0 0<br>
/dev/vg2/var /var reiserfs
noatime 0 0<br>
<br>
So, no -A...<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">-X can be useful if you have extended attributes, lots of systems
don't.</pre>
</blockquote>
</blockquote>
<br>
Dunno if I do or not... how would I tell?<br>
<br>
Would including -X cause a problem if there are none?<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<pre wrap="">This is Gentoo specific but other distributions are moving this way.
Gentoo has the USE=caps and caps-ng settings which means to use file
capabilities flags instead of SetUID to root to perform certain
privileged tasks. This means that programs like ping and traceroute
can be allowed to do the one privileged network function that they
need without chmoding them +s and forcing them to run with full root
privileges. -X is needed to copy these flags.
</pre>
<blockquote type="cite">
<pre wrap="">-H is for hardlinks, I don't usually see many of them around.
</pre>
</blockquote>
<pre wrap="">
In Gentoo and others /usr/share/zoneinfo is full of hard links. There
are others around the system too. If you want to check your /usr for
hard links run this:
find /usr -mount -type f -links +1 -ls</pre>
</blockquote>
<br>
Ummm... that does find a lot of links, but they all seem to be soft
links, not hard links?<br>
<br>
Most are links to other files in the same directory.<br>
<br>
Is -H only about hard links? Or all links?<br>
<br>
Looks like a ton of soft links in /usr/bin too...<br>
<br>
Sadly, this is an ancient system, and only has 2GB of RAM...<br>
<br>
The issue with memory is only about Hard links?<br>
<br>
Any way to do a test to see if it will run out of memory during the
actual run?<br>
<br>
If it does, would cp run into the same problem?<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">I've not seen a Gentoo system in a long time, but if /usr just
contains installed packages then I think you won't see any of the
above. But if you add them, they don't harm. It will just take more
time and maybe use more memory.
For example -H will use more memory if I'm not mistaken. If you
don't have enough memory, it might crash.
</pre>
</blockquote>
<pre wrap="">
- -H will use more memory according to how many hard links it finds. If
it runs you out of memory then you have tons of them and not using -H
would probably run you out of disk space.
</pre>
<blockquote type="cite">
<pre wrap="">But I don't think it is usually a problem these days. But if Gentoo
builds all the packages in /usr/src andd lots of source still
exist, it might be very large.
If you do have a /usr/src or /usr/local or something like that. Are
they on the same filesystem ?</pre>
</blockquote>
</blockquote>
<br>
Yes... and while /usr/src only contains the kernel sources,
/usr/portage contains all of the other system/application sources. I
could move that, but I'd rather not right now.<br>
<br>
Total size for /usr isn't *huge*, but is about 13.5GB.<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">If not, you want -x to prevent them being copied as well.
You can obviously easily check if there is anything else mounted
under /usr by checking the mount command and/or /etc/fstab
I've never used -s
</pre>
</blockquote>
<pre wrap="">
- -s is --protect-args. It is often used in scripts so they can handle
any weird path someone might tell the script to copy. It is important
if you have spaces in your source or target parameter.</pre>
</blockquote>
<br>
So, since I'm doing this manually, it isn't needed?<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">I don't see any reason for using -p or -P for partial files,
because if copying doesn't succeed you'll probably just start over.
There is no network to worry about.
</pre>
</blockquote>
<pre wrap="">
- -P is also shorthand for --progress. On a local only copy
- --whole-file is forced so --partial is irrelevant.</pre>
</blockquote>
<br>
Ok, scratch -p and -P...<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<pre wrap="">When using rsync from an other machine, which uses other
uids/gids, I would always recommend to add:
--numeric-ids
</pre>
</blockquote>
<pre wrap="">
If networking were involved I would completely agree with this. If
the live CD has duplicate usernames with different numbers badness can
happen.</pre>
</blockquote>
<br>
So, to be safe, use --numeric-ids...?<br>
<br>
<blockquote cite="mid:529D007D.40003@sanitarium.net" type="cite">
<blockquote type="cite">
<blockquote type="cite">
<pre wrap="">Are the trailing slashes required/important/necessary?
</pre>
</blockquote>
<pre wrap="">
Yes, you need to use them when you are working with directories.
Anyway, on most Linux distributions, moving the content of /usr
shouldn't be a big event.
Because the system doesn't change the content of /usr it usually
just contains programs, libraries and other files from installed
packages.
Don't worry, to much.
If it's a mailserver, what you could do is:
- shutdown - unplug the network - do everything you need to do to
copy the files and change fstab - check if everything starts up
normally - plug network back in
If with the check something fails, reboot with the livecd again and
fix any problems.
Because the mailserver isn't connected to the network, no mail was
lots or bounced.
I assume this is a standalone mailserver that doesn't depend on an
external database. A mailserver shouldn't bounce mail if DNS isn't
working for a little while.
Something else you could consider is to not automatically start the
server processes and first check that everything works. Don't
forgot to enable them to start automatically again when everything
is done ;-)
Hope that was useful for you.</pre>
</blockquote>
</blockquote>
<br>
Yes, thanks to both of you!<br>
<br>
<div class="moz-signature">-- <br>
<br>
Best regards,<br>
<br>
<b><i>Charles</i></b><br>
</div>
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